Digital imagery speeds up insect identification for PCAs

Digital imagery speeds up insect identification for PCAs

Today's digital revolution - including Smartphones, handheld microscopes, and attachable lenses - help identify insects at warp speed. This helps PCAs to write insecticide prescriptions quicker and get insecticides applied in the field faster to reduce crop damage from pests.

Today’s digital revolution is delivering an arsenal of technological tools to the business of agriculture  - including Smartphones, portable microscopes, and other devices - to help pest control advisers (PCAs) and crop growers more quickly identify and manage destructive insects.

In the end, these digital tools can help increase farm efficiency and profitability, critical keys to remain economically viable in today’s global agriculture.

This technology, says University of Arizona Entomologist John Palumbo, provides precise and faster insect identification crucial in the battle against crop pests. Palumbo, PCAs, and growers are tapping these digital tools to help launch a faster war against destructive insects.

“Digital imagery has come a long way over the last 20 years,” says Palumbo, based at the Yuma Agricultural Center in Yuma.

About 20 years ago, Palumbo leaped into early digital technology to more quickly identify pests found in Arizona low desert farm fields located around Yuma.

Palumbo discussed digital imagery opportunities with PCAs and others at the 2014 Desert Ag Conference in Chandler, Ariz. in May, sponsored by the Arizona Crop Protection Association.

Palumbo says more and more PCAs and growers are aboard the digital bandwagon. Some are snapping excellent close-up photos of pests on plants or the soil. The digital images are texted or e-mailed to entomologists at local universities for faster insect identification.

He compares this time-saving process to earlier years when a PCA or grower snail mailed an insect to a land-grant university where an entomologist identified the pest. The results were then mailed back. The mailbox-to-mailbox connection generally required 7-10 days or longer.

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Today’s digital communications allows a PCA to write pesticide prescriptions quicker faster. This in turn allows faster insecticide applications which can negate serious crop damage, and save the grower thousands of dollars over the long haul.

Something better

Palumbo never took photography courses. He just had an intense interest in technology as a possible route to accelerate the insect identification process.

“I am not a photographer and never had any formal training in photography,” Palumbo said. “I don’t even know what an F-stop is.”

When Palumbo joined the UA more than two decades ago, he embraced the new digital revolution. The university invested in a $15,000 digital microscopy - a digital microscope with a camera on top.

Palumbo says the device captured great close-up images of insects which were saved on a small disk. Absent in those days was connectivity to a laptop. Company and personal e-mail was in its infancy.

“We used the digital microscopy to take a closer look at the physical characteristics of insects,” Palumbo said. “In aphid species, we honed in on the eyes, wing venation, and antennae to make a positive identification. Digital microscopy was great back in the day.”

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Around 2010, the UA purchased a digital SLR camera for Palumbo for $1,300 – specifically a Sony alpha 65 with a 2.8/100 macro lens – the camera the bug specialist still uses today.

“I don’t know what the description of the camera means but I get really good photos with it. The camera comes in real handy.”

With the camera and macro, Palumbo can almost see the tarsal pads on the prolegs of the cabbage looper and the hair on the ends.

The future is now

In the past, a microscope was necessary to capture such fine details. On a lady beetle, Palumbo captured the tiny antennae and mouthparts with the camera.

“High quality cameras allow you to capture good imagery,” Palumbo said. “If I sent the image to another expert for insect identification, they could probably give me a pretty good indication of the insect species.”

More recently, Palumbo (the UA) purchased a handheld Dino-Lite digital microscope for $350 – smaller in size than a small TV remote. It connects by a USB cable to a laptop, desktop, or via wireless to an iPad or iPhone.

Palumbo showed various PowerPoint slides taken with the digital microscope. One was an image of sweet alyssum cuttings in a petri dish. The picture was so intricate that the entomologist saw tiny larvae on the foliage.

The device delivered an image Palumbo had never seen below – an up-close view of a lygus nymph.

The microscope also shoots real-time and time-lapse video which allows Palumbo to witness the feeding habits of insects on plants.

A PCA or grower can use this microscope to snap close up photos while seated behind the steering wheel in a truck, and then wirelessly forward the image to an entomologist for identification.

Aphid identity

Palumbo says identifying different members of the aphid family can be quite a challenge. He shared a microscope-gathered photo of an aphid with a dark abdominal patch, plus antennal tubercles (small horns) extending inward from the base of the antennae.

“I knew within a reasonable doubt the insect was a green peach aphid.”

Palumbo also discussed the high quality digital imagery captured with his Smartphone. Just 4-5 years ago, most PCAs and growers used flip phones to communicate. Today, Smartphones with built-in cameras can capture up to 18 megapixels of photo quality.

“If used properly with a steady hand, a Smartphone can capture excellent insect images,” Palumbo said.

Katydid search

On the average, Palumbo receives 1-2 insect images per week from PCAs and growers to identify the pests. One photo clearly showed a katydid in lettuce. The question was…what species?

Palumbo, an Internet Google surfer, searched for ‘katydid desert Arizona’ on the Internet. The first result was a photo of a creosote bush katydid from the Arizona Sonoran Desert Museum website. The webpage said this katydid type prefers to eat creosote but will not partake of lettuce.

In this case, the insect had wandered from the desert into the lettuce field but posed no crop threat. No chemical used was needed.

Especially difficult to identify are insect eggs, Palumbo says. He may have an idea of the actual insect but cannot truly identify the identify via the eggs.

Palumbo purchased a low cost 10X Smartphone lens attachment – which when held tightly against the Smartphone camera lens – provides the extra detail to see eggs close up and identify the insect.

Macro lens

Palumbo shared about a digital product purchased by UA entomologist Peter Ellsworth, based at the Maricopa Agricultural Center. Ellsworth attaches a magnetized macro lens on the Smartphone camera lens to gain excellent insect close-ups. The lens cost – a non-bank account breaking $10.  

Palumbo has propped 15X and 20X magnification hand lenses against his Smartphone camera lens. Crucial to capturing crisp photo details is steady hands.

In summary, Palumbo calls digital imagery an important tool which PCAs and growers can use to determine if an insect is a ‘friend or foe.’

“Fast pest identification is  a foundation for decision making on the farm,” Palumbo concluded.

(Note: The mention of brand names in this article is not an endorsement by Western Farm Press. There are numerous, high quality digital brands and devices available on the market today.)

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